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FOA still head

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FOA still head

Postby jokkman » Mon Nov 03, 2014 12:55 am

FOA was developed by the Swedish military ”science lab” first for making rocket fuel (old “gasoline rockets”) in the field but someone discovered that it was a fast still head and the secret was out :-)
The FOA head is more of a catalyst that makes spirit, the original sized FOA is around 200mm of height, and can handle about 500W power in the kittle. It looks almost like a “trumpet” and have always been in discussions about how god it really is …. I dont think its the best still head for neutral but its one of the best "allround" still head (in my opinion).

One other thing with the FOA is that it requires little water when you run it and its easy to handle. No thermometers and other stuff, you run it “old school” on feeling. The only thing you adjust is the cooling water (maybe some ground adjusting on the heating to).
You get about 70-75% product directly from standard mash with a FOA, and you still have flavor on the product. So it’s about 2-3 plates in one run with a FOA and its pretty fast for a small “thing” ;-)
Because the original FOA just can handle about 500W people start to scale up the FOA to handle more power (Watt on the heatelement) and to be faster. I use a FOA that is 2 times larger than the original FOA, you just take every measurement and multiply with 2.
Now you have a FAT-FOA, its about 450mm of total height and still takes very little water in the runs. A FAT-FOA can handle up to 2000W power, I usually run my with 1000W power.

So you get 70-75% product with flavor in one run with a FAT-FOA, now you want to get 94%+ neutral product?
Just mount a column under it, 1000mm length 34mm diameter and put 10 scrubbers in it and you are there!

Then you start to wonder about making Gin…. If you build a ginbasket (Bombay style) and put it between your kittle and FAT-FOA you now can make Gin. I recommend that you first do a neutral run with column under and then dilute your product to a 12-15% "mash" and run it again with just “ginbasket” and FAT-FOA mounted.

I have been testing a lot of ides with my FAT-FOA and my FOA doesn’t look so nice anymore…. But there is 2 things I recommend that you should do if you decide to build a FOA.
1. Put separate water connections, 1 for reflux cooler and one for product cooler
with a vent on the outgoing water. If you do so you can easy fine adjust you FOA runs regarding the result you are after or speed
2. Replace the “long left pipe” with a longer pipe that you “twist around, like a spiral” so you get on a FAT-FOA about 1000mm pipe instead of 400mm pipe on the left side. Look at the pics and you understand what I mean.

I like the FOA based on its simplicity and speed, also that I have one head that I can do neutral, gin, rom and a lot of other spirits by simply add a column/run without column, add a ginbasket and so on its like “all in one” still head :-)

Uploading some pics on really nice build FAT-FOA and original FOA, this isn’t my build its just so beautifully build by a Sweed called “lillis”. I also put up original drawings and a pic on the “spiral improvement” on the FOA and some other pics so you can see FOA parts before welded together
One last thing, when people start to build a FOA they are confused about the “reflux return” from the upper part of the head, you should only have a couple of mm gap there. You hammer together the end part of the tubing so you get on a FAT-FOA maybe 6mm gap at the end.




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I am not a complete idiot, some parts are missing....
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Re: FOA still head

Postby just sayin' » Mon Nov 03, 2014 2:48 pm

Thank you for posting your FOA here, Jokkman! I have been interested in the FOA for years, but have read mixed reviews on how it runs. I am happy to see your positive results. Interesting little machine! More picture of your FOA would be much appreciated.
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Re: FOA still head

Postby zapata » Mon Nov 03, 2014 4:54 pm

I have to admit I don't get it. I see a cooling management type reflux condenser, 5 different routes/directions for possible vapor management style vapor splitting, 2 different routes for air cooled liquid reflux return, and finally a product condenser with a vapor lock.

Can someone walk me through the theory here?
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Re: FOA still head

Postby jokkman » Mon Nov 03, 2014 5:42 pm

It works like a CM but also with vapor steam speed, making it go round in the "head". On “blue print” pic vapors enters in the left tube from the "main column" and goes around and in to the "FOA column" on the right bottom part.
Then some of the vapors cools down and become liquid/reflux and drops down through a small hole in the bottom of the "head column" to the packing/kittle.
The vapors that doesn’t “reflux” sucks up through a hole in the top of the "FOA column" by the passing vapors and circulates in the right tubing again, and some of it exit in the right tubing 25mm from the top center and are going from there to a condenser and become product.

So If you have the reflux condenser in “full effect” you get no product, like on a CM head.
In a FOA the vapors always enter in the left tubing, never straight up like in conventional columns. The end part of the "upper center column" have just a small gap so the steam takes the easy way, left tubing.
it also never enters the column from the top because its easier to go straight forward for the vapors, and when the vapors pass the head column it makes a suction and get some of the vapors that in the end become product.
I know a lot of guys have been staring at the blue print for days and just say, i don get it....
I build one and run it and compare how it heats up the tubing, what tubing gets warmer first. Full speed on the reflux condenser = no product and so on...
From that result i understand how i works, but the first time i saw the blue print I didn't get it at all :smile:

The FOA head have an other name to. its called Otto (female name), "Otto the spirit catalyst"... FOA stands for the swedish military department that develop it, i think "Otto" was the "code name" on the project when it was developed.
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Re: FOA still head

Postby jokkman » Tue Nov 04, 2014 4:06 am

ha ha, I just read my post and found some typo's.... Otto is a male name, not female name :lol:
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Re: FOA still head

Postby Zombie » Wed Nov 19, 2014 1:46 pm

"I know a lot of guys have been staring at the blue print for days and just say, i don get it.... "

LOL I just did on the other thread! Point proven!!!

I may need to be "put down" soon.
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